The battle lines are drawn. The armies are lined up. The guns are loaded. But here in Copenhagen, a phony war is underway.

For the past two days, negotiators have been bogged down in minor technical details and endless delays. For hours plenary meetings have been taken up by countries complaining about the process. Then finally solutions are agreed, and everyone files out to the relevant gatherings – only to find them cancelled on arrival. All of Monday disappeared down that hole.

Today, it looked like some real work was getting done. But with just hours left before the ‘high-level’ segment (with ministers, and – increasingly – heads of state themselves) begins, several different texts were in circulation, all laden with square brackets (indicating disagreement) around even minor issues of contention that should have been resolved last week.

At this rate, Copenhagen will not only fail, it will be a disaster.

Of course, these conferences – especially high-stakes ones like this – never end that way. Some face-saving arrangement is always cobbled together. But the question now is when the phony war will erupt into open hostilities – and whether heads of state will be able to resolve them in the time they have left.

The biggest question, one which has bedevilled climate negotiations for more than a decade, is finally reaching crunch point – about whether developing countries, which were exempted from taking on carbon emissions targets by Kyoto, will finally agree on binding measures to rein in their future emissions.

Everyone agrees that industrialised countries should act first; that much was agreed as far back as 1995. And some can claim to have done so, in Europe at least. But the Bush Administration lost us a decade, and time has now run out: science demands that for temperature rises to be limited to 1.5 degrees, and carbon concentrations eventually returned to 350 parts per million, global emissions must peak by 2015.

It is no accident that both India and China oppose any mention in the negotiating text of this global peaking year, or of an eventual target for atmospheric carbon levels of 350ppm. They know that accepting these limits necessarily implies that their era of high-carbon growth is over. For these science-based targets to be met, India cannot burn all its coal. Nor can China. Nor can South Africa. They must shift to low-carbon growth, and they must start that shift now.

In fairness, no-one is arguing that developing countries should take on mandatory Kyoto-style reductions right now. Instead the debate is around how far their future emissions must depart from the ‘business-as-usual’ baseline. The small island states – who stand to lose most as sea levels rise – now argue that developing countries should aim for 15-30% below baseline by 2020. China and India say they will never accept this.

The United States is also central here. America will never ratify Kyoto – everyone knows this. But the Obama administration has come here offering serious targets, of initial 17 per cent cuts below 2005 levels by 2020. It could deepen this ambition, but Obama faces a tough (if not impossible) battle to get any climate plan through the Senate, and the administration also knows that it is politically toxic domestically to take on any improved target unless China does likewise.

These are the two main belligerents facing each other over the trenches here at Copenhagen. In the next day or two the cannons will open fire. When the dust dies down, we will see whether we still have a habitable climate left.